Finkeel for boats with foldable leeboards

ABSTRACT

The invention relates to a finkeel ( 2 ) for boats, having of a fixed part ( 3 ) attached to the hull ( 1 ) and a movable part comprising two leeboards ( 4, 5 ) that can be orientated in an independent manner.  
     According to the invention, each leeboard ( 4, 5 ) consists of at least one upper element ( 4   a   , 5   a ) hinged to the fixed part ( 3 ) of the finkeel and a lower element ( 4   b   , 5   b ) hinged to the upper element, so that the leeboards can be folded up towards the fixed part ( 3 ) of the finkeel, to achieve lateral overall dimensions smaller than the width of the hull.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Italian Application No.M12005A001253, filed Jul. 1, 2005, the teachings of which areincorporated herein by reference.

BACKGROUND

The invention relates to a finkeel for boats, in particular sailingboats.

As is known, many sailing boats are equipped with a finkeel whose mainfunctions are to assist the righting of the hull inclined by the actionof the wind on the sails, and to prevent or in any case limit the leewayof the hull on the water.

In modern boats it is common practice to mount at the end of the finkeela bulb containing lead or some other heavy material, suitable to form aballast which increases the righting effect of the hull with the sametotal weight of the finkeel.

In order to improve this effect, finkeels have also been designed thatare able to swing to the right or left relative to the longitudinalmid-plane of the hull, moving the bulb away from the centre of gravityof the boat and therefore increasing the righting moment, which is theproduct of the weight of the bulb multiplied by the arm of the weightforce (i.e. its distance from the centre of gravity).

For this purpose, the finkeel is hinged at the bottom of the hull and isrotated with respect to its hinging axis by means of actuators,according to needs.

This type of finkeel is effective as regards righting of the boat, butit has limitations due to the fact that by rotating the finkeel in themanner explained above, the transverse resistance to the leeway of thehull decreases significantly owing to the smaller resistingcross-section of the rotated fin keel, without providing any advantagesas regards the draught and therefore the possibility of access totourist ports.

In order to overcome this problem, the Applicant of the presentapplication has designed in the past a particular finkeel for boats,described in European patent application EP 1.464.572; the fin of thiskeel is composed of a fixed part which is solid with the hull, andsupports at its end two hinged leeboards that can rotate independentlyof each other.

This solution has produced interesting results and the present inventionaims at developing them further; for this purpose it would beadvantageous to increase the length of the leeboards hinged to the fixedpart of the finkeel, so as to augment the righting moment of the boatresulting from the product of their weight and that of the ballast bulbspresent thereon, multiplied by their distance from the centre of gravityof the boat.

This possibility, however, is subject to a limitation as regards thelength of the leeboards which, when they are rotated through 90° (i.e.are horizontal), should not exceed the maximum width of the hull sinceotherwise problems could arise during maneuvering in tight spaces asoccurs, for example, in ports.

The technical problem underlying the present invention is therefore thatof providing a finkeel with movable leeboards having a greater length,all other conditions being the same, than that of known leeboards,without however causing problems due to of an excessive width inrelation to the hull.

SUMMARY

The idea for solving this problem consists in designing a finkeel withfoldable leeboards; to this end each leeboard comprises a first elementhinged to the fixed part of the finkeel and a second element hinged tothe first element, so as to form together a structure which may befolded up in a manner similar to that bird wings.

DESCRIPTION OF THE DRAWINGS

The characterizing features of the invention are recited in the claimsappended to this description; they will emerge more clearly in the lightof some exemplary embodiments of the invention, illustrated in theaccompanying drawings wherein:

FIGS. 1 and 2 show schematically a perspective view and a stern view ofa hull with a finkeel according to the invention, in respectiveoperating conditions;

FIGS. 3 and 4 show, respectively, a side and a front view of anembodiment of a finkeel according to the invention;

FIG. 5 shows a variant of the finkeel in FIGS. 3 and 4;

FIGS. 6, 7 and 8 show a side view of a further embodiment of the finkeelaccording to the invention, in respective operating conditions.

DETAILED DESCRIPTION

With reference to the drawings, in them numeral 1 denotes overall thehull of a boat equipped with a finkeel 2 according to the invention.

This finkeel comprises a fixed part 3 integral with the keel of the boatand on which two foldable leeboards 4 and 5 are hinged.

The latter are in turn composed of two elements 4 a, 4 b; 5 a, 5 b whichare hinged together and which support at the bottom two ballast bulbs 6,7.

As can be seen in FIG. 2, the leeboards 4 and 5 may be folded upunderneath the hull 1 so as to remain within its maximum width(indicated by broken vertical lines); to this end the finkeel 2 isprovided with systems for rotating the upper elements 4 a, 5 a, withrespect to their hinging axis X to the fixed part 3, and the lowerelements 4 b, 5 b, with respect to the hinging axis Y to the upperelements.

In accordance with a first solution shown in FIGS. 3 and 4, the upperelements 4 a, 5 a are each rotated by a respective gear mechanism whichcomprises a pinion 10, 11 and a gearwheel 12, 13 mounted on a pin 14, 15solid with the element 4 a, 5 a.

The pinions of the gear mechanisms are actuated by respective motors(not shown in the drawings) or by hydraulic pistons which mayadvantageously be accommodated in the fixed part 3 of the finkeel 2.

The lower elements 4 b, 5 b of the latter are instead rotated withrespect to the upper elements by means of hydraulic cylinders 18, 19.

The leeboards of the finkeel thus formed are folded up by rotating theupper elements 4 a, 5 a through operation of the gear mechanisms 10-13,and the lower elements 4 b, 5 b, through operation of the hydrauliccylinders 18, 19.

In this connection it is worth to emphasize the importance of the fixedpart 3 of the fin keel.

Indeed, it allows movement of the axis of rotation X away from the keelof the hull, allowing rotation upwards (i.e. through an angle greaterthan 90°) of the upper elements 4 a, 5 a of the fin keel, since they donot interfere with the hull; the leeboards may thus be folded up in amanner similar to that of bird wings (FIG. 2).

The variant of the finkeel 2 shown in FIG. 5, where the same numberingof the parts already described has been maintained, differs from thatdescribed above in that for rotating the upper elements 4 a, 5 a,another hydraulic cylinder 20, 21 is used instead of the pinions 10 and11, with the associated motor.

In this case the hydraulic cylinders 20, 21 have the function ofoperating the gear mechanism which moves the—gearwheels 12 and 13integral with the pins 14, 15; in order to favour the action of thecylinders 20 and 21, the fixed part 3 of the finkeel has openings wherethey are advantageously accommodated.

By way of a further possible embodiment of the invention, FIGS. 6 to 8show the example of a finkeel where, when it is in the verticalcondition of FIG. 6, the hinging axis Y of the lower elements 4 b, 5 bis perpendicular to the drawing sheet of FIGS. 6-8 and to the hingingaxis X of the upper elements 4 a, 5 a.

In order to rotate the lower elements with respect to the upperelements, in this variant hydraulic cylinders 24, 25 are used and act inthe plane of said elements: before, during or at the end of thisoperation, the upper elements 4 a, 5 a are rotated with respect to theirhinging axis X.

FIGS. 7 and 8 show the sequence of these operations for the leeboard 5of the finkeel; a similar sequence is also performed for the leeboard 4(although it is not shown in the drawings), the upper element 4 athereof, however, is rotated about the axis X on the opposite side tothe corresponding element of the leeboard 5, with respect to thevertical mid-plane of the boat defined by the fixed part 3 of thefinkeel.

As can be seen, this solution also allows folding up of the leeboard 4and 5 of the finkeel underneath the hull, so as to cause them to retractinto its widthwise overall dimensions; differently from before, in thiscase the hydraulic cylinders 24, 25 operate in the plane of the lowerelements 4 b, 5 b and may therefore be aligned with them, beingaccommodated inside the upper elements 4 a, 5 a which do not haveopenings as in the example—of FIG. 5.

Finally, it should be noted that in all the above cases the leeboards 4and 5 of the finkeel 2 may be rotated on the same side with respect tothe mid-plane of the boat defined by the fixed part 3 of the finkeel, soas to increase the righting moment, like it occurs in the known finkeels, for example such as that described in patent application EP1,464,572 in the name of the present applicant.

All of these variants nevertheless fall within the scope of the claimswhich follow.

1. Finkeel for boats, having a fixed part to be attached to the hull, amovable part comprising two leeboards hinged to the fixed part androtatable independently of each other with respect thereto, wherein eachleeboard comprises at least one upper element hinged to the fixed partand a lower element hinged to the upper element, so that the leeboardscan be folded up towards the fixed part of the finkeel, to obtainoverall dimensions smaller than the width of the hull.
 2. Finkeelaccording to claim 1, wherein the hinging axes of the upper elements andlower elements of the leeboards are parallel.
 3. Finkeel according toclaim 1, wherein the hinging axis of the lower elements is perpendicularto the hinging axis of the upper elements.
 4. Finkeel according to claim1, comprising means for rotating the upper elements and lower elementsof the leeboards.
 5. Finkeel according to claim 4, wherein the means forrotating the elements which form the leeboards comprise gear mechanismsand/or hydraulic cylinders.
 6. Finkeel according to claim 1, whereinballasts are attached at the ends of the leeboards.
 7. A boat comprisinga finkeel according to claim 1.